<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<style>
    body {
        width: 300px;
        position: relative;
    }
 
    .aside {
        width: 100px;
        height: 200px;
        float: left;
        background: #f66;
    }
 
    .main {
        height: 200px;
        background: rgb(17, 128, 255);
        overflow: hidden;
    }
    .parent{
        width: 100px;
        height: 100px;
        background: red;
    }
    .child{
        width: 50px;
        height: 50px;
        background: yellow;
    }
</style>
<body>
    <div class="aside"></div>
    <div class="main"></div>
    <div class="parent">
        <div class="child">111</div>
    </div>
    <script>
    </script>
</body>
</html>
